FK8 front suspension question

I want to ask that Does for FK8 Honda civic type r MacPherson struct will really reduce the steering torque comparing to double wishbone suspension. I noticed that for early FWD sport cars are 4 double wishbone suspension, but those new type R cars are special MacPherson struct on the front and multilink at back. Is it a better solution for a motorsport FWD or not.

I'm not familiar with the chassis', but some general thoughts.

The decision usually comes down to packaging, with struts taking up less engine compartment intrusion.

With multi-link strut based suspensions a good compromise can be reached with geometry and packaging - it may not be the best of both designs, but they generally avoid the worst compromises.

Which is best in practice for "motorsport" is hard to guess, as scrub radius (especially for wider wheels), front or rear steer, camber gain/loss, and type of 'racing' are just some of the factors to consider.

The length and mass of the driveshafts also has an influence on whether a FWD vehicle has torque steer or not. Subaru's and Audi's tend not to be affected by it, as they run a longitudinal drive train layout, meaning that the differential is on, or very close to, the center line of the vehicle so that the driveshafts are of equal length and mass. Vehicles with a Transverse mounted engine will quite often have the differential mounted well off of the center line of the vehicle, so they end up with unequal length driveshafts and are more likely to have torque steer occur when there are changes to the torque load being delivered to the front wheels, this can also be apparent under braking as well.

Me bad, I was thinking the torque - steering effort - needed to steer the car, not torque steer.

As Steven said, and to counter driveshaft variations causing the problem, some manufacturers will use an intermediate shaft on the 'long' side so equal length shafts can go from there to the wheel hubs,you may find that low level, entry models have the uneven shafts, but high end, more powerful versions of the vehicle have the intermediate, which can be a simple upgrade from the vehicle wrecker's/dismantler's yard.

Some will use a larger diameter on the long shaft to equalise the torsional stiffness.